Requerimientos del cultivo

Introduction

The years from 1963 to 1966 were the busiest of the lunar landing project, no less for science planners than for the spacecraft and rocket builders. After the major decisions made in 1962 provided a basis for planning, the Office of Space Sciences called on its academic advisory bodies to define first the broad outlines of a program of lunar and planetary exploration, then more specific plans for the moon, based on the clearer definition of the Apollo project that was emerging during the period.

Scientific Interest in the Moon

In the two and a half centuries since Galileo first turned his crude telescope on the moon, astronomers have mapped its surface features, measured the height of its mountains and the depth of its craters, and calculated its size, mass, and orbital parameters with increasing accuracy over the years. Even so, the best optical telescopes, under the best observing conditions, could not show any detail smaller than about 300 meters across (1,000 feet, about the size of the capitol building in Washington); so informa- tion concerning the nature and texture of the surface was limited.

To the telescopic observer, the moon's surface shows two distinct types of regions: 1. the maria (Latin="seas"; singular mare) - dark, apparently smooth, and roughly circular areas extending over hundreds of kilometers; and 2. the highlands, mostly mountainous regions much lighter in color. Among the most striking features are the craters - tens of thousands of circular depressions ranging in diameter from 180 miles (290 kilometers) down to the limit of telescopic resolution. Most large craters have high walls and a depressed floor, and many have a central peak or ridge. Some are centers from which streaks of light-colored material (rays) extend for considerable distances. Besides the craters, the lunar

surface shows domes, ridges, and rilles - long, narrow channels resembling dry watercourses - that run for several kilometers.1 _{Measurements of reflected light indicate that the lunar surface is covered with} a layer of finely pulverized material. Airless and arid, the lunar surface is subjected to temperature changes of more than 200 degrees C (360 degrees F) during the course of a lunar day.2

For decades these features fascinated astronomers and cosmologists, who have generated volumes of speculation as to the moon's origin and history. Three hypotheses attracted adherents: one, that the moon was spun off from a molten proto-earth; a second, that the moon was formed in a separate event and later captured by the earth; and the third, that the earth and moon formed at about the same time in the same region of space (this hypothesis was considered somewhat less likely than the first two). Those who believed the moon was formed by accretion of smaller bodies generally supposed that during its evolution the moon, like the earth, went through a molten stage in which its components were chemically fractionated, with iron and nickel being separated from the rocky minerals as the moon cooled. A smaller body of opinion held that the moon never grew large enough to be completely melted by the heat generated as its component particles coalesced, and would not be chemically differ- entiated.3

All of these assumptions led to difficulties when examined in light of accepted celestial mechanics. If the moon separated from the earth at some early stage in its formation, its orbital plane should lie in the plane of the earth's equator, but it does not. If, on the other hand, the moon was formed elsewhere in the solar system, its capture by the earth would be highly improbable and its present orbit difficult to account for. Finally, if the earth and moon were formed out of the sane primordial matter by any mechanism, it is hard to explain the fact that the earth is nearly half again as dense as the moon.₄ None of the hypotheses could be proved or disproved on the basis of the evidence available from visual observation alone. Both led to logical conclusions concerning the chemical composition and internal structure of the moon that could not be tested. Scientists who held that the moon was once molten regarded the mafia as massive lava flows from volcanoes or fissures in the lunar crust, similar to known examples on earth, and pointed to the domes and certain craters that are much like well known terres- trial volcanic structures. Advocates of the "cold moon" theory considered the maria to be the solidified remains of large bodies of molten rock created by collision with meteorites or asteroids, or perhaps by localized heating due to some other cause.5 _{The origin of lunar craters was a matter for debate. Some} had undoubtedly been produced by impacts of cosmic debris, but strong arguments could be made that others were volcanic in origin. It was generally accepted that the moon's surface, unaffected by wind and water, preserved a record of cosmic events which the earth must also have undergone; on earth, however, the effects have been obliterated by erosion.6

Crucial to the confirmation of either hypothesis, or to the creation of an alternative, was information that could be obtained only by direct examination of the moon. Analysis of samples of the lunar surface would show whether the moon was chemically similar to the earth and whether the lunar material had ever been extensively melted. Measurement of the flow of heat from the moon's interior to the surface would show whether it was still cooling from a molten state. Other important investigations included the seismic properties of the moon, which could reveal its interior structure. Some of this information could be provided by instruments, perhaps including remotely controlled samplers capable of returning lunar material to earth. But some tasks, such as examining the moon's surface and selecting samples on

the basis of that examination, could better be done by humans. With the advent of the space age, lunar scientists could look forward to sending instruments to the lunar surface; only after the decision to land people on the moon could they hope to send a trained explorer.

Planning for Lunar Exploration

Homer Newell set lunar exploration planning in motion in 1962 with the appointment of the Sonett committee on Apollo scientific experiments and training [see Chapter 2]. After three months of consul- tation with leading experts in the scientific fields related to lunar exploration, the committee outlined its conception of the scope of Apollo lunar science. The primary objectives were examination of the lunar surface in the immediate area of the landed spacecraft, geologic mapping of the landing area, investigation of the moon's interior by means of emplaced instruments, studies of the lunar atmo- sphere, and radio astronomy from the lunar surface.7 _{No specific experiments were recommended, but} the criteria used in developing the objectives limited the possibilities. The experiments should be sci- entifically important and feasible, possible only on the lunar surface and only with a human on the mission, and likely to lead to further scientific and technological development.8

A week after the Sonett committee issued its draft report, NASA committed Apollo to lunar-orbit rendezvous. This decision, probably the most thoroughly debated of the entire program, directly af- fected the scope of lunar science. The mission mode determined how many men and how much equip- ment could be landed on the moon. Whereas the other possible modes (direct ascent and earth-orbit rendezvous) contemplated a single large spacecraft that would land with its entire three-person crew on the moon, lunar-orbit rendezvous would put down a separate specialized landing craft and a crew of two.9

With that decision made, Associate Administrator Robert C. Seamans, Jr., asked Newell to present several questions to NASA's outside scientific advisers for discussion. What should be the preferred scientific objectives of the earliest lunar landings? Would the acquisition of scientific data require more than two persons on the moon at the same time? Were there sufficient scientific reasons to establish a semipermanent station on the moon for extended exploration? Advice on these questions would be important in establishing policy with respect to lunar science and could have direct influence on the design of the lunar landing craft.10

An appropriate forum for such a discussion was already in session that summer - the first summer study conducted by the Space Science Board, meeting on the campus of the State University of Iowa [see Chapter 2]. Manned space science programs were not the study's primary concern, but two working groups, one on lunar and planetary exploration and one on the scientific role of humans in space, provided opportunities to examine the plans for Apollo's experiments and put some of the scientists' concerns on record.11

At the start of the summer study the chairman of the Space Science Board, Lloyd V. Berkner, instructed the participants that their advice on the existence of a national space program and the division of effort among its projects was not sought. Nonetheless, because of mounting fears for what it would do to NASA's space science budget, Apollo was never far below the surface, and objections to the manned programs were repeatedly voiced. Berkner, Newell, and others tried to steer the discussions into more

productive channels, such as how the capability being developed for Apollo might be exploited for scientific purposes; but many of the participants could not be dissuaded from protesting the priority assigned to the lunar landing project.12

Seamans's questions were aired, in substance at least, and the summer study's final report contained recommendations concerning the points he had raised. The working group on the scientific role of humans in space endorsed the findings of the Sonett committee but recommended that experiments that only used the moon as a base for observation (e.g., radio astronomy) be relegated to later missions. It found that there was indeed a valid scientific requirement for a lunar surface laboratory for long-term investigations. The working group on lunar and planetary exploration reached similar conclusions and called for increased emphasis in the Ranger and Surveyor programs on providing necessary engineer- ing information for Apollo.13

Of much more concern to the summer study participants was the scientific competence of the men who would land on the moon. Acknowledging a continuing need for astronauts whose primary skills were in spacecraft operation, the study report nonetheless urged the inclusion of a professional scientist among the crew of the first lunar landing mission. To ensure that such a person would be ready for the first landing, NASA should recruit qualified scientists at once and begin training them as astronauts. The science community insisted that these scientist-astronauts be given the means to maintain their scien- tific competence while acquiring piloting skills. To that end, a space institute should be established convenient to the astronaut training center, a facility "of the very highest scientific calibre [maintain- ing] liaison with major centers of research in the space sciences [and functioning] as a graduate school offering advanced degrees in various fields of science." It should either be operated "under contract with a major university" or administered by "that office of NASA responsible for scientific research and planning,"14 _{(i.e., the Office of Space Sciences). This "space university" proposal - which Newell} later remarked never had the slightest chance of being accepted by NASA15 _{- was soon abandoned, but} the demand for scientist-astronauts was reiterated by the science community right down to the end of the Apollo project.

With the modifications made by the Iowa summer study and with the imprimatur of the National Academy of Sciences, the Sonett committee's recommendations formed the framework of Apollo's initial lunar science planning. Shortly after its establishment in July 1963 the Manned Space Science Division promulgated the first scientific guidelines for Apollo, which reflected this preparatory work. The primary scientific activity was to be the study of the moon itself. First priority among the various lunar studies was given to geologic mapping, followed by collection of samples for return to earth and emplacement of instruments to return data by telemetry.16

Headquarters-Center Relations in Science

While working out arrangements for cooperation with the Office of Manned Space Flight, Newell and his staff also had to establish working relationships with the Manned Spacecraft Center (MSC). In early 1963 MSC's only experience with science had been the visual and photographic experiments made on the first three Mercury orbital missions.17 _{These somewhat hurriedly improvised "experi-} ments" produced some useful data, but mainly they served to show that people could conduct scientific exercises in orbit.18 _{They also showed that both scientists and engineers had much to learn about each} other's objectives and methods. One result was that MSC acquired a reputation among space scientists

of being at best indifferent and at worst hostile toward scientific investigations.19 _{Eugene Shoemaker,} always an enthusiastic supporter of manned space flight, was "utterly dismayed" by the attitude of the MSC representatives at the Iowa summer study: "we don't need your help; don't bother us." This expe- rience led Shoemaker to agree to spend a year at NASA Headquarters to try to establish a lunar science program; unless someone concentrated on that task, lunar science might never get done at all, because "there was no planning for it [and] no program for it."20

Some of MSC's indifference to science was the predictable consequence of the formidable develop- ment tasks the center faced and its intense concentration in 1962 on learning to operate in space. But Newell felt that the Houston center's engineers and managers (also engineers, for the most part) simply did not appreciate what space science and manned space flight could do for each other. Houston had no scientific research under way; the few scientists who worked there were mostly inexperienced in re- search and served almost entirely in support roles, providing data to the engineers. Newell spent con- siderable effort in 1963 trying to create a more receptive attitude toward science at MSC.21 _{One of} Shoemaker's first accomplishments after he came to Headquarters was to persuade MSC to expand its small Space Environment Division, a branch of the Engineering and Development Directorate that existed mainly to collect environmental data affecting the design of spacecraft and mission plans. One geologist joined the division in 1963, and a team of specialists from the U.S. Geological Survey was assigned later that same year. Their functions were to set up a research and training program in geology, develop a model of the lunar surface for use by the spacecraft designers and mission planners, assist in the evaluation of lunar scientific instruments, and develop plans for geologic field work on the moon.22 Lunar surface science, though important, was only part of the larger question of manned space science, and Newell, looking ahead to the earth-orbital flights of Gemini and Apollo, wanted to establish a place for science on those missions as well. The agreement worked out between Newell and Brainerd Holmes for developing experiments called for the appropriate manned space flight center (usually MSC) to oversee the development of experiment hardware once the basic design had been worked out by the Office of Space Sciences. As OSS saw it, this would require more scientific competence than the Houston center had. Up to mid-1963 MSC's concern for experiments had been limited to assuring that they fit into the spacecraft and the flight plan and did not compromise a mission, a task carried out by an Experiments Coordination Office in the Flight Operations Division.23 _{Now, OSS saw a need to} establish what would amount to a space sciences division at Houston. Discussions with MSC produced agreement that the Space Environment Division would be the nucleus of the prospective science branch.24 The Office of Space Sciences and the Manned Spacecraft Center spent the rest of 1963 defining their relationship. Newell firmly maintained his office's responsibility for all of NASA's science programs, while MSC occasionally displayed reluctance, to say the least, to accept direction from Headquarters.25 In the old days of NACA the field laboratories had enjoyed considerable independence in the conduct of their programs, and all of MSC's top managers were old NACA hands. At times they seemed in- clined to insist on running their programs their way, including the science. But by the end of the year MSC had agreed in principle to set up a scientific program manager on Director Robert Gilruth's immediate staff, and Headquarters and center elements were beginning to work out a description of that person's responsibilities.26

Lunar Surface Experiments

Early in 1964 the Office of Space Science and Applications (OSSA) began to define the Apollo lunar science project more narrowly. Rather than issue a request for experiment proposals to the scientific community at large, which was the usual procedure for soliciting experiments, Newell and his manned space flight counterpart George Mueller agreed that initially a few selected scientists should be called upon to identify the most important experiments within the areas agreed on by the Sonett committee and the Iowa summer study. A representative of Headquarters's Manned Space Science Division and the chairman of the Space Science Board then compiled a list of experts who met on January 30 to begin the process.27 _{The first investigations agreed on by this planning group comprised geology (field} geology, petrography and mineralogy, and sample collection), geochemistry, and geophysics (seismol- ogy, magnetic measurements, heat-flow measurements, and gravity measurements). For each area the group suggested several prominent scientists to work out detailed experiment plans.28 _{In April the first} Apollo science planning teams, groups of experts in subdisciplines of the earth sciences, began meet- ing to define more specifically the lunar surface experiments and instruments. Later, teams would be established for lunar atmospheric studies and biosciences.29

At Houston, meanwhile, mission planners had started defining the lunar landing mission in detail. In late 1963 the first set of operational ground rules was established, listing mission objectives and con- straints and identifying critical points where a flight might have to be aborted or diverted to an alternate mission in case of failure of some essential system. Using these ground rules and the latest available weight and performance data for the launch vehicle and spacecraft, planners then prepared the "refer- ence trajectory," a detailed description of the mission from liftoff to splashdown.* For planning pur- poses the reference trajectory listed 10 landing sites within a zone 85 miles (137 kilometers) wide and 1,480 miles (2,380 kilometers) long stretching along the equator on the moon's visible side. It assumed